Cross wind landings

[Chuck Ellsworth]

(Cessna 152/172. Floatplanes now ... "what's a crosswind?")

Rivers can subject you to x/winds.

[Big Pistons Forever]

Personally I have found the sideslip method the easiest for low time pilots. While the kick out the crab seems easy, in practice timing the kick out is hard for low time pilots as it occurs at the time of maximum work load in the landing flare so that they are either too late which means the aircraft is crooked when it touches down or too early which means the aircraft will touch down with significant sideways drift.

I tell students to hold a crab until about 300 feet above ground on final and then align the aircraft with the runway centerline and adjust the lateral displacement ( ie whether you are left or right of the runway centerline) with bank. If the airplane is drifting downwind add more bank if the aircraft is moving upwind reduce the bank.

Don't worry about coordination. Do what ever it takes with the rudder to keep the airplane pointed straight down the runway but deliberately adjust the bank to attain/maintain the aircraft position over the middle of the runway.

[9 lives]

It is possible to touch down on, and hold only the upwind wheel on the surface, though this is a rather extreme demonstration.




I remember the first time I landed an Ercoupe in a strong crosswind, I was really worried, as it had no rudder pedals. I had no choice, I just flew the centerline, and it all figured itself out as I touched down. Since, I have found it easier to just fly the plane, and not worry so much about the details of how I did it.

[Johnm]

Is it normal to feel this aprehensive?

If it gives you a clue.....I have 1200 hours and an instrument rating and still get the equivalent of "stage fright" before every flight. Should that stop I'll assume I've become "cocky" and give up flying.

[wood73]

I was struggling with the crosswind, as the first instructor I did it with had me hold the crab and kick it off last second, I could never quite get it spot on as I suppose this will come with experience.


Another instructor suggested kicking off the crab at some point between 100-200' giving plenty of time to stabilise the approach before the flare and this worked for me perfectly and although I'm only 35 hours into training, I have successfully landed a c172 with 12kts crosswind with no drama, using this method, this may not sound much to experienced guys but to us beginners its an achievement as when I was having trouble first time around it was only an 8-9 kts crosswind.

[FleetFlyer]

Having spent many a happy hour in a Jabiru, I can confirm that it can be a little challenging in crosswinds. The reason for this is that it has too little rudder area, though this was addressed on later models.

If I remember correctly, it could run out of rudder in a crabbed approach/kick straight scenario. The highest crosswind I ever landed in was about 25 knots at Le Touquet. Because they have a very long runway I was able to minimise the crosswind component by landing at 70 kt, no flap and one wheel at a time. It was a case of flying it on and holding it down. There's no way the crab technique would have been successful in that wind.

I suggest that when the wind is right you get your instructor to demo a few landings while you sit back and take it all in. Sometimes a just watching someone do something well will improve the way you it. God knows I'm better at snooker after I've watched the world champs for a few hours.

[Genghis the Engineer]

Originally Posted by jabba pilot

I'm flying a jabiru lsa, 80 hp. Not thr easiest, but a great training plane. Have to always use correct rudder input. Scary sometimes, but fun.

I certainly have found the Jabiru one of the more challenging aeroplanes to land well of my career, mostly because of the cockpit ergonomics. I'm assuming that yours is like the one I've flown, with the Y-shaped yoke in between the seats, and a brake lever in front of that.

The aeroplane, as I recall, responds adequately to either the crabbed or wing down approach - so do whichever your instructor is teaching you. I tended to use wing down.

The problem with the Jabiru is that it's then virtually impossible to maintain aileron input after touching down, as the only sensible way to fly it, particularly from a shorter runway, is to put your right hand through the middle of the yoke, locking the ailerons neutral, and holding the brake lever. Pulling back for maximum braking, in a significant crosswind, is wise, because that minimises the time when you've got a crosswind on the ground but can't use aileron to help balance it.

So:-

Wing down method (steer with aileron, keep on centreline with rudder)

Let it touch down on one wheel if necessary, flaring as usual.

Once settled - centralise aileron, put your hand through the middle of the yoke, pull firmly back on the brake lever whilst keeping straight with the rudder pedals.


Not an easy aeroplane to land at-all, but should make a good pilot of you.

And if your instructor is telling you something different - listen to him, not me ! It's his aeroplane, and I'm sure he has more hours on type than I do.

G

[FleetFlyer]

And another thing -if you find the crosswind to be outside the capability of the rudder to hold the aeroplane straight whilst you're holding the nosewheel off, then put the nosewheel on the ground. In a Jab its directly connected to the pedals rather than castoring so you can use it to stop yourself from being blown off the runway.

This should only be done on smooth runways though, the nose leg is very snapoffable.
Also, as G says, do what you're comfortable with. If you've run out of rudder to kick it straight then you've probably bitten off more than you can chew crosswind-wise at your relatively early stage of the game.

However, if you get good at a Jabiru it will make you a good pilot, they're slippery, trickier than average to land, but not difficult. Also, 90% of everything said on forums about their engines is bolleux, they're perfectly reliable, and if you can't make an engine failure over land survivable in something that will fly as slowly as 40 knots then you probably shouldn't be flying at all.

Have a look at this, filmed in Genghis's back yard.

[jabba pilot]

Big Pistons Forever, Genghis, and Fleet Flyer, you all make good sense and make it sound very " do-able". Starting to look forward to trying it for real!
Thank you for straightforward advice. Video's great, and its really great to hear from other Jabiru pilots.

Makes sense to keep it as simple as possible

Good to hear of another learner. Sounds like you are well on the way

[dirkdj]

You have to remember that the test pilot who did the 'demonstrated crosswind component' demonstration is required to display 'average' piloting techniques. I understand this to mean he made no crosswind compensation whatsoever and really only demonstrated how much sideload the landing gear could take. It is not very often that you can do better than the test pilot.

[FleetFlyer]

Actually, I'm pretty certain the test pilots do use techniques to compensate for the crosswind when getting the 'max demonstrated' crosswind figure. There's little point in demonstrating the maximum sideload that the undercarriage can take when it can be calculated in the design office. The test is one of the handling of the aircraft rather than just the strength of the gear.

I'm sure G will be along momentarily to fill us in more fully though. He knows all about this kind of thing.

[Pilot DAR]

It is not very often that you can do better than the test pilot.

Sure you can!

Very often when I test fly a modified type, it's the first time I've flown that type, let alone the mod. I know what I'm looking for, and that is an an aircraft which is not demanding unusual piloting skill. I regularly meet other pilots with lots more skill on type than I have. Though I try to fly with grace, I will fly with precision. If with precision, compliance is demonstrated, then the grace I can manage is a bonus!

Crosswind testing is not a strength test of landing gear, but rather a confirmation of controllability. When I'm testing an aircraft modified with an external load, which could increase weather cocking (more vertical area behind the C of G), the continued crosswind compliance becomes important.

A float installation most commonly will affect crosswind capability, thus additional vertical tail surfaces, usually a ventral fin, are added.

An installation like this:



Can result in a lot more control being required to keep it straight in a crosswind. I flew this plane 100 miles to get to an airport which was that day 19G25 directly across the runway, and I did eight landings in both directions. Sometimes full rudder was required to be applied and held, along with aileron while rolling on the runway, but it was controllable. Were it not, we would have had to consider an increase to the rudder area.

During my crosswind testing of this aircraft:



The winds of the day were 35 knots at 45 degrees to the runway heading (no matter which of the four runways I chose). The modified plane complied with the requirement for crosswind handling - which for a Caravan is demonstrated to 20 knots. In this photo, you can see the finlets, with are required when the floats are installed.

Sorry about the photo size, photobucket refuses to resize it!

[Pace]

Pilot Dar

Do you know how demonstrated is achieved ?
Is it purely a crosswind component that the pilot has landed the aircraft in during certification or a figure he estimates the average pilot can handle with that aircraft!
Demonstrated is just that it's not a limiting crosswind component as I once found landing a Seneca with 40 kts crosswind wherei was convinced it would be a touch and go but ended up a touch and stop as the aircraft handled it

Pace

[India Four Two]

The FAA requirement for light aircraft is that the maximum demonstrated crosswind is 20% of Vso.

Some manufacturers don't bother to go beyond this requirement, even though the aircraft is capable of managing higher crosswind components.

For example, the DG1000 glider has a ridiculously low maximum demonstrated crosswind component of 8 kts, which is 20% of the gross weight Vso. However, the manual then states "Strong crosswind offers no problem", without defining "strong"!

There is an interesting older discussion on this topic: http://www.pprune.org/tech-log/38029...on-please.html

[Pace]

Thanks for that! Normally the OM is the rule book in event of exceeeing limitations published there.
In the event of having an accident while landing at much stronger winds than the demonstrated are there insurance problems in doing so ?

Pace

[Genghis the Engineer]

There's only a limited amount of science in determining the demonstrated crosswind limit, here are the main bits of CS.23 - the European light aircraft standards. Other standards are pretty similar.

CS 23.745 Nose/tailwheel
steering
(a) If nose/tailwheel steering is installed, it must be demonstrated that its use does not require exceptional pilot skill during takeoff and landing, in crosswinds and in the event of an engine failure or its use must be limited to low speed manoeuvring.
(b) Movement of the pilots steering control must not interfere with correct retraction or extension of the landing gear.

CS 23.1585 Operating procedures
(a) For all aeroplanes, information concerning normal, abnormal (if applicable) and emergency procedures and other pertinent information necessary for safe operation and the achievement of the scheduled performance must be
furnished, including –

(1) An explanation of significant or unusual flight or ground handling
characteristics;

(2) The maximum demonstrated values of crosswind for take-off and landing and procedures and information pertinent to operations in crosswinds;

(And some of the interpretative material later on)

(3) Approach and Landing. The steady gliding approach, the pilot skill, the conditions, the vertical accelerations, and the aeroplane actions in 23.75(a), (b), and (c) are concerned primarily with not requiring particularly skilful or abrupt manoeuvres after passing the 15 m (50ft) point. The phrase ‘steady gliding approach,’ taken in its strictest sense, means power off. However, it has generally been considered that some power may be used during a steady gliding approach to maintain at least 1.3 VS1 control sink rate on final approach. For those aeroplanes using power during approach, power may be decreased after passing the 15 m (50ft) point and there should be no nose depression by use of the longitudinal control. For those aeroplanes approaching with power off, the longitudinal control may be used as necessary to maintain a safe speed for flare. In both cases, there should be no change in configuration and power should not be increased. The landing distance and the procedure specified in the AFM are then based on the power used for the demonstration. The power used and the technique used to achieve the landing distances should be clearly stated in the AFM. This applies to portions of the approach prior to and after the 15 m (50ft) height. The aeroplane should be satisfactorily controllable when landing under the most unfavourable conditions to be encountered in service, including cross winds, wet runway surfaces and with one engine inoperative. Demonstration of landing with an adverse crosswind of at least 0.2 VS0 will be acceptable and operation on wet (but not contaminated) runway surfaces may be simulated by disconnecting osewheel steering. The effect of weight

What does all this mean in practice. Basically the test team - ideally with a well instrumented runway (anemometers close to the threshold are nice) will go up, start into wind, and slowly increase the crosswind, and in some cases tailwind components by repositioning and picking their conditions.

Eventually one of two things will happen:-

(1) You've met or exceeded the 0.2Vso value, AND you can't find anything worse - so you declare the demonstrated crosswind limit at the worse you've seen.

(2) The team actually reach conditions which they consider require "exceptional piloting skill", so they wind it back by a few knots and declare a demonstrated crosswind limit about there.

Defining "exceptional piloting skill" is tough - but as a working rule HQR 5 or above on the Cooper Harper scale would be a good basis.



One thing is also worth adding - the comment that you can't expect to fly the aeroplane better than the test pilot, is almost certainly untrue. A test pilot is a man or woman with many professional tasks - not just flying, so they are not necessarily as sharp in the cockpit as a full time professional pilot who does nothing but fly. Also, at the end of a light aircraft certification programme the most experienced test pilot on type maybe has 200 hours on type? Give it a few years and there will be working pilots with 1000+ on type, and who fly nothing else. So, it would be a bit worrying if there weren't, eventually, pilots who can fly it better than the test pilot did.

I've certainly safely landed aeroplanes that I had low 3-figure hours on type, significantly beyond the "demonstrated crosswind limit" in the book, and I'll bet plenty of other people here have too.

G

[Pull what]

Crosswind landings catch a lot of pilots out at all levels, ive sat by some horendous attempts in large aircraft, I can only say thank God for strong U/Cs!

For my money the easiest method on any aircraft is cross controls after the threshold, its also what all the autoland systems use on the large aircraft Ive flown.

You need to also get a decent crosswind to practice and that can be difficult. I spent an hour once in a 35 knot crosswind in a Cessna 150 practicing landings and that was one of the most useful Ive ever spent on any training exercise and the methios that I eventually perefected that day was the method that also worked many years later on the Airbus etc..

Teaching removing the drift(not kicking, a phrase and instructor should never use) before touchdown is far too hit and miss for the average PPL student and if he gets it wrong will loose tbe centreline immeadiately.

Also, at the end of a light aircraft certification programme the most experienced test pilot on type maybe has 200 hours on type? Give it a few years and there will be working pilots with 1000+ on type, and who fly nothing else. So, it would be a bit worrying if there weren't, eventually, pilots who can fly it better than the test pilot did.

Umh not sure if I agree with that. A test pilot is already an exceptional pilot. Many pilots with many 1000s of hours are not exceptional pilots at all and never will be, in fact some have very mediocre skills and some also have deterioating judgement skills as they get older. Ive sat by young first officers with hundreds of hours who are far more skilled that older pilots with thousands of hours on type.

Trying to achieve performance better that the manufacturers test pilot is foolhardy and unnecessary. A demonstrated figure however is not limiting, as the limit is only reached when full contol deflection is reached. What you do need to consider though that the manufactures test pilot has not tested the stability of the aircraft at the point of full control deflection during a crosswind landing.

[Genghis the Engineer]

In terms of performance - absolutely, because the TP has a brand new aeroplane, and is concentrating on hitting exactly the right numbers.

In terms of of handling, only sometimes. I'm pretty sure that any current member of the Red Arrows can do more within the envelope with a Hawk than John Farley could when he was test flying it - and that's not to denegrate John who is one of the best test pilots Britain has ever produced and outside the envelope will have done stuff that would be totally alien to most current Hawk pilot.

Test Pilots are very good pilots, but handling skill is only a part of that skillset; most pilots will never be that good in the aeroplane, but some will be better.

G

[thing]

I was taught the crab technique from day one on gliders, which I learned to fly before powered, due I suppose to the long wingspan low ground clearance of gliders. When I learned powered my instructor, who is also a gliding instructor, asked me what xwind technique I used on gliders and I told him; so he said that I may as well use it in powered as it was what I was used to.

I've never had a problem with the 'kick off' drift method, I don't think it requires superhuman skills or timing (can't do if I can do it!).

Next bit of the story. In later years I got to know a GA instructor who is also a 757 captain. He is a disciple of the wing down method, which he uses while flying the 757 and teaches as a GA instructor. He explained it as mentioned in previous posts with the addition of, and I paraphrase, 'If you can't keep straight on the centreline using the rudder on the approach you know you are going to run out of control authority when you land it, so it's a safety check as well as a valid method of landing xwind; plus when you land you already have the 'correct' cross controls applied.' The more I thought about this the more it made sense. So I tried doing a few wing down approaches when landing xwind. I was surprised by how little 'wing down' you need even in quite strong xwinds.

The problem I have at the moment with this technique is I have to think about it when lining up for final, it's not intuitive to me like a crab landing is. I suppose it boils down to how you were trained in the first place but having tried both methods, and I'm sure I would get familiar with the wing down technique the more I use it, they are both valid for most GA aircraft and basically it's boils down to whatever floats your boat. Or aircraft across the centreline...

[Pull what]

The problem I have at the moment with this technique is I have to think about it when lining up for final, it's not intuitive to me like a crab landing is.

So dont use this method on final, crab down to threshold then use crossed controls

'

If you can't keep straight on the centreline using the rudder on the approach you know you are going to run out of control authority when you land it,

Thats sounds very odd to me, Ive never heard of any airline pilot trying to keep straight on the approach using rudder plus any pilot that thinks that tbe crosswind component at 3-4 miles out is going to be the same at 30 feet cant have flown many approaches of any sort!